On Sun, May 30, 2021 at 6:16 PM Mauri Sandberg <maukka@xxxxxxxxxxxx> wrote: > Add documentation for a general GPIO multiplexer. > > Signed-off-by: Mauri Sandberg <maukka@xxxxxxxxxxxx> > Tested-by: Drew Fustini <drew@xxxxxxxxxxxxxxx> > Reviewed-by: Drew Fustini <drew@xxxxxxxxxxxxxxx> After some thinking I realized these bindings should not be restricted to just input. There exist electronic constructions such as open drain that would make it possible to mux also outputs. > .../bindings/gpio/gpio-mux-input.yaml | 75 +++++++++++++++++++ Rename it just gpio-mux.yaml > +$id: http://devicetree.org/schemas/gpio/gpio-mux-input.yaml# Also here > +title: Generic GPIO input multiplexer Generic GPIO multiplexer > +description: | > + A generic GPIO based input multiplexer Not just input > + This driver uses a mux-controller to drive the multiplexer and has a single > + output pin for reading the inputs to the mux. Make this clearer and do not mention "driver". Here is a suggestion: This hardware construction multiplexes (cascades) several GPIO lines from one-to-many using a software controlled multiplexer. The most common use case is probably reading several inputs by switching the multiplexer over several input lines, which in practice works well since input lines has high impedance. Constructions with multiplexed outputs are also possible using open drain electronics. > + For GPIO consumer documentation see gpio.txt. No need to mention this I think, not your problem :D > + pin-gpios: I still want this renamed like in my previous mail. Hope all is clear! Yours, Linus Walleij
